Elision (French)

In French, elision (élision) is the suppression of a final unstressed vowel (usually ) immediately before another word beginning with a vowel or a silent $⟨h⟩$. The term also refers to the orthographic convention by which the deletion of a vowel is reflected in writing, and indicated with an apostrophe.

Written French
In written French, elision (both phonetic and orthographic) is obligatory for the following words:
 * the definite articles le and la
 * le garçon ("the boy"), la fille ("the girl")
 * le + arbre → l'arbre ("the tree"), la + église → l'église ("the church")
 * the subject pronouns je and ce (when they occur before the verb)
 * Je dors. ("I sleep") Ce serait génial. ("That would be great.")
 * J'ai dormi. ("I slept.") C'était génial. ("It was great.")
 * but: Ai-je imaginé ? ("Did I imagine?"), Est-ce utile ? ("Is that useful?")
 * the object pronouns me, te, se, le, and la (when they occur before the verb)
 * Jean se rase, la voit, me téléphone. ("Jean shaves himself, sees her, phones me.")
 * Jean s'est rasé, l'a vue, m'a téléphoné. ("Jean shaved himself, saw her, phoned me.")
 * but: Regarde-le encore une fois. ("Look at him one more time.")
 * the object pronouns le, la, moi, toi when they occur after an imperative verb and before the pronoun en or y:
 * Mettez-le, donne-les-moi, casse-toi. ("Put it, give me them, scram.")
 * Mettez-l'y, donne-m'en, va-t'en. ("Put it there, give me some, leave.")
 * the negative marker ne
 * Elle ne parle plus. ("She isn't talking anymore.")
 * Elle n'arrête pas de parler. ("She won't stop talking.")
 * the preposition de
 * Le père de Jean vient de partir. ("Jean's father just left.")
 * Le père d'Albert vient d'arriver. ("Albert's father just arrived.")
 * que (which has many different functions)
 * Que dis-tu ? Que Jean ne fait que manger. ("What are you saying? That Jean does nothing but eat.")
 * Qu'as-tu dit ? Qu'il ne nous restait plus qu'une semaine. ("What did you say? That we only had one more week left.")
 * The conjunction si plus the pronouns il and ils
 * si elle aime les chats ("if she likes cats")
 * s'il(s) aime(nt) les chats ("if he/they like cats")

Elision is indicated in the spelling of some compound words, such as presqu'île "peninsula", aujourd'hui "today", and quelqu'un "someone".

At the beginnings of words, the aspirated h forbids elision. Example: Le Havre. The mute h, however, requires elision. Example: l'homme. Both types of "h" are silent regardless.

Informal French
Elision of the second-person singular subject pronoun tu, before the verbs beginning with a vowel or mute h (silent h), and of the particle of negation ne, is very common in informal speech, but is avoided in careful speech and never used in formal writing:
 * Tu as décidé de lui rendre visite, tu es allé voir le film, tu n&apos;étais pas là, je ne sais pas. "You decided to visit them, you went to see the film, you were not there, I don't know." (careful speech)
 * T'as décidé de lui rendre visite, t'es allé voir le film, t'étais pas là, je sais pas. (informal speech)